Electronic Fireworks Firing Panel

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Ok so I decided to start a new thread since I took the other one so far off into this topic.
Other thread: http://www.diyaudio.com/forums/showthread.php?s=&threadid=33482

Based on all the great advice I've been given here, I now have the joy of redesigning my circuit. I really don't want to do it on paper. What is a good easy to use program to design schematics visually? Preferrably not completely text based input. I need easy to use. Price doesn't matter (yo ho ho).

If I can do that I'll post it here so you guys can really tear it apart and find the flaws.

Another question I have. I'm using 2 12V batteries in a series for 24V. When figuring out what resistors I need for my LED's, what voltage should I base my math on? Should I equate based on the high end of the operating range, or tha average? 24V or 26-27V?

Any ideas on the best prices for LED's with chrome holders(5mm)? I need red and green...


li_gangyi : I used that power supply designer you linked me to and worked out a supply with parts they had in stock that would turn my 24V into 12@2A. Pretty sweet little program they have there. The problem I see is I don't know if I can solder that small at this point. I'm still learning lol. IC's scare me, and I didn't even know what some of the components listed were. Granted, the sytem the software designed only had about a dozen components, which is sweet. And they would put it all together in a kit for like 30 bucks. I think a simple 12V battery will be the cheaper way to go. This year at least. Next year I'll have to make some improvements, so that could be one. Plus I don't like building things I don't understand. I didn't really understand how that PSU worked. Neat little site though.
 
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OK , you have 2 batteries in series to get 24v.

If you are using the 12 volts for low current stuff, like LEDs and the power for relays, just use wires from the positive and negative of ONE of the batteries in series. You can leave them hooked up for 24v, just tap one battery for 12. Doesn't hurt a thing except drains the battery thats hooked to the 12 v stuff a little faster.
 
yupz...I actually gave him a link to the National's SMPSU design webby...you can try the through hole parts...but if you really wanna go the cheapie way the 12V using one battery trick will work well...so what is the main thing the the control panel has to give out?? Voltage...Current?? some specs posted here will help us to help you...lolx
 
Variac said:
If you are using the 12 volts for low current stuff, like LEDs and the power for relays, just use wires from the positive and negative of ONE of the batteries in series. You can leave them hooked up for 24v, just tap one battery for 12. Doesn't hurt a thing except drains the battery thats hooked to the 12 v stuff a little faster.

I didn't know I could do that!

The only thing the 12V will be used for is to switch relays on and off for the 24V signal to the firing slats. It will allow me to user lower rated(and much cheaper), rotary switches and pushbuttons.

The LED's will be in the 24V circuit though, so I know I have to use resistors for them.

I'm working on making my schematic in CircuitMaker 2000 right now. I wish it had more components. Is there any other similar software I can use?
 
li_gangyi said:
so what is the main thing the the control panel has to give out?? Voltage...Current?? some specs posted here will help us to help you...lolx


The main thing the panel has to give is voltage. It's travelling over more than 100 ft of 18 guage wire, and I need it to be responsive. The electronic matches the system fires only need about 40-60 mA to fire, but the higher voltage makes em fire quick. Especially when firing numerous matches at once, which involves numerous runs of 100ft+ 18ga wire.
 
Having a very hard time finding inexpensive 24V rated rotary switches and pushbutton switches. This system has the ability to fire up to 6 cues from one button, and obviously I'll be able to push more than one button at once. This will increase the amperage going through whole the system(I think?), particularly the rotary switches and pushbuttons. Please tell me I'm wrong and It probably won't really ever go over 3 amps on each rotary or pushbutton, and I'll scrap the relays.

I've been having my doubts about whether or not I was way overestimating the current draw of this system. I just don't want to be a victim of blown components. But I don't want to be a victim of overkill(and overpay) either.
 
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Joined 2002
If the matches you use are the same as we use in the UK, ( I assume they must be, usual Chinese?), then I used to use 48v for the firing circuit, it gives a lot more leeway for long cable runs with cheap wire.

A mate also made a 24V version with 10000uf caps that was great for slow rate, but large numbers of simultaneous firings.
 
Ok so I finished my schematic. I'm no electrical engineer, but I think it looks ok.

So I guess help me figure out if I screwed anything up guys, or if you see any better ways of doing things.

http://home.comcast.net/~faithblinded/bgpics/schematic.gif

It's really too big to look at the whole thing at once, so use your picture viewer of chioce. I think all my symbols are correct, though I haven't really labeled anything beyond what the program did automatically when I put it together.

I'm really getting excited about this project. This schematic will be worth the time I spent on it when I build the board. Just to share my plans further: My cabinet builder buddy is making the firing panel with a clear acrylic top and bottom. Once I get the top piece drilled with all my holes right where I want em, I'm gonna make up a photoshop file that is a big label for the underside of the top acrylic sheet. Then I'll take it to my local vinyl graphics shop and have em print it up. Then when I finish the panel it'll look alll kinds of pimp. And as a bonus, you'll be able to flip it over and look at the mess of wires and what not inside. Bonus wow factor lol. I'm a dork I know.
 
Also, to avoid the question, the 2 grid's up at the top are what's called "slats". The pins represent bolts poking through the top of a square box. You take a shooting wire(2 cond wire w/all clips on both ends), and clip an aliigator to each bolt, then clip the other ends to the ignitor. That completes the circuit. I didn't bother drawing all 6 slats, which is why there are the 4 8 pin connectors connected to nothing. Well, tear it up guys.
 
Bill, I'm glad to see there is no continuity tester in this schem. The only safe way to do it with E-matches or any ignition device is to use a phase-locked loop. I get very nervous when I see some deisgns that rely on a resistor or voltage divider to limit current to the match for checking continuity.
Ricky
 
It's do-able and obviously works as his designs are respected, but nothing says that one match might be built a little differently and WILL fire at say, 20 or 30ma. Variations in manufacturing make it difficult to but a threshold on when the matches will or won't fire. All of the commercially available controllers use a phase locked loop and sends a very small signal down the circuit under test and listens for ringing, it kinda turns the wire and match into a small transmitter and if there is a load it shifts the frequency and and the circuitry senses it and lights up an led. The advantage is that is uses less than 1ma to sense and it does so at high frequency whick travels down the wire much further and is also safer to use. The method works the same way a metal dectector works. The presence of metal, or a match in this case, disrupts the signal being sent out and where a metal detector would beep, an led lights to tell you it's good. It's a really simple circuit actually, it may just sound a little complicated.
 
Where would I get started on a system like that? Are there any sort of DIY designs out there for that kind of continuity testing? If you could set me down the right path here I'd appreciate it. I don't necessarily think that's something I'd apply this year, but perhaps as an upgrade... If I can get an understanding of the other kind of system you're talking about maybe I'd lean that way.

Sounds expensive though. Care to elaborate any more?
 
How bout if I built a simple tester for the e-matches, that applied the same amperage as my continuity circuit, to use before allowing any of them to be wired up. If it burns up in the tester, oh well, better there than in the midst of testing cues. What do you think about that as a workaround? My show will be small, so it would prolly be 150 e-matches or less to test...
 
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